I’m revisiting my setup for residential deadbolts and want a durable boring jig that stays square on fiberglass doors — considering the HPC 6011MC (2–1/8" cross bore, 1" edge bore) but curious how the Pro-Lok INJIG-108 has held up for you. If you’ve paired your jig work with a go-to strike reinforcement like StrikeMaster II Pro with 3" screws, what’s delivered the best real-world security and clean fitment over 12 months?
@OP INJIG-108 stays square on fiberglass; tape under clamps. StrikeMaster II Pro with 3" screws is solid; pre-drill.
HPC 6011MC tracks fine, but reverse‑score fiberglass first. StrikeMaster II Pro + two 4in hinge screws helped most, @OP.
@emerson_l99, I’ve been running the INJIG-108 on fiberglass; pad the clamp feet with thin neoprene and swap the pilot for a 3/16 brad-point (‘slow speed, no clutch’) and it stays square. The 6011MC works too, but its guide bushings loosen faster in gelcoat dust, so keep a spare 2–1/8 bushing and wax the hole saw to keep it cutting clean. For the jamb, Door Armor’s long strike with 3.5" screws staggered high/low has given me the best real-world hold without splitting.
Quick tip: @maddie_l99’s pad idea is great — add a 3/4" MDF backer inside and “finish from both sides” with a sharp 2–1/8" hole saw; zero gelcoat blowout on fiberglass. If you run the 6011MC, swap the latch bore to a brad-point or Forstner at low RPM with a touch of paste wax on the teeth. For door hardening, Door Armor MAX (3.5" screws) has been kinder to wavy jambs in my installs; want a link?
On fiberglass, my 6011MC stays square once I skin the clamp faces with UHMW tape and wax the 2–1/8" saw teeth with paraffin — cuts cleaner, less gelcoat chatter. @emerson_l99 the INJIG-108’s held up fine for me too, but check the set screws weekly. For reinforcement, Door Armor MAX with 3.5" screws has outperformed the common 3" screw strike kits in call-backs.